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mckelvey. SEDIMENTARY MINERAL DEPOSITS 



[Ch. 27 



TABLE 2 



Value of 1946 Domestic Production of Minerals from Sedimentary Deposits 



All minerals listed below have been produced from sedimentary deposits. Some, 

 as shown, were not produced domestically in 1946, and a few have never been mined 

 in this country (an important amount of the foreign production is derived from 

 sedimentary deposits — for example, columbium and tin concentrates, gem stones, 

 monzonite, and manganese). The production figures for individual minerals are 

 rounded off to the nearest $1,000, and no more than three significant figures are 

 given. The value of the production of placer tungsten, ilmenite, rutile, zircon, 

 sharpening stones, vanadium (produced as a by-product from phosphate rock), and 

 potash salts are confidential and cannot be released separately. A. F. Mathews of 

 the Bureau of Mines, who cooperated in many ways in the preparation of this table, 

 has furnished a figure for the total value of these minerals, which is included in the 

 total. John Crawford, D. F. Davidson, and Robert Boardman of the U. S. Geolog- 

 ical Survey assisted in the tabulation and checking of the data. 



Explanation of Symbols 



? Small part of production may have come from non-sedimentary rocks. 

 ?? Part of production known to have come from non-sedimentary rocks; value 



estimated. 

 ??? No production figures available; value estimated. 

 X Confidential; value included in grand total. 



I. Detrital deposits 



A. Placer concentrates 

 1. Metals 



Chromite None 



Columbium and tantalum concentrates None 



Copper (chalcocite, native copper, etc.) None 



Gold $ 20,700,000 



Lead (galena) None 



Magnetite None 



Mercury 2,000 ?? 



Platinum metals (refined) 



Platinum 1,270,000 ? 



Palladium 4,000 ? 



Iridium 300,000 ? 



Osmium 45,000 ? 



Rhodium 78,000 ? 



Ruthenium 5,000 ? 



Silver 63,000 



Tin None 



Titanium concentrates 



Ilmenite X 



Rutile X 



Tungsten concentrates (scheelite, wolframite, hub- 



nerite) X 



Total value of metals produced from placers $ 22,500,000 



